Note that NookColor does not support PDB files.

I too am enjoying trying to use ADE with my nook color.  I have bought ebooks from BookDirectory.co.uk.  These must be put into ADE then transferred to my nook.  Or at least that's the theory!  Once I have read them on my nook, should I try to access them again, the dreaded 'user not activated' message appears.  And sometimes it happens even before I've read them.  I then reauthorize the nook, wait for the synch and discover that maybe 1/3 of my books are now missing and I can't access them.

Now for the sting in the tail - BookDirectory has told me they will no longeer be selling ebooks - they cannot guarantee the quality of service (gee, I know why).  I have until 30 June to re-download all of my purchases and lose them again in the ADE cloud!!

Is there any way to ensure that the library on ADE doesn't lose my nook's authorization and then lose my books?

Thank you in anticipation for any help

Um - the nook isn't losing it's brains; ADE is.  ADE tells me the books are missing.  My nook knows they are there.  ADE has duplicate copies of books and tells me they are missing.  It's the ADE list that is always wrong and it's ADE that seems to go loopy. ADE is not my library manager of choice; it was forced upon me by BookDepository.  Therefore, I only open it when I really need to - like to re-authorize the nook or download a book from BookDirectory. 

If I do a hardware reset on the nook, I will lose books because ADE does not know where they are.  ADE does not 'have' the book; it just lists the title and tells me it is missing.  It appears to have lost the link between its 'key' and the actual book location.

I frequently have the nook connected via wifi or the USB.  I am beginning to suspect that if I connect the nook and ADE isn't opened it gets all upset and takes its toys and goes home (de-authorizes the nook, should such a word exist).  I shall do some testing to confirm my theory.  Should I be correct, I will have to open ADE every time the nook is anywhere near the computer just to keep it happy.  What a needless complication.  Anybody already done this and can save me the time?

Watch this space for results of testing.

This copy of ADE is on my home MAC.  No  one else uses it.  ADE authorised the computer using my Adobe ID which is my email address which has not changed since I started using Adobe Forums about 9 years ago.  So - what other user does it think it is dealing with?  My cat is computer illiterate..... Come to think of it, he is totally illiterate - can't read either.

About 25% of my books are missing or showing errors.  Some of the errors are file open errors - error #2038.  Some don't even show an error message when I try to access them - just have error printed in one of the columns.  Very helpful.

I'm beginning to suspect that ADE is corrupted but am afraid to uninstall it and re-install in case it loses everything!

Somebody please explain to me why I ever got involved with this piece of software???!!!!

I feel for you!  I'm having the same problem.  After several weeks of trying to get some answers from ADE, (they didn't know anything, or the site was down, or they just tossed me off into this never ending spiral to nothing), I finally got a somewhat coherant response to this problem. 

Now, I have about 600 ebooks, some from Barnes and Noble, some from a Christian book store, which has really helped me! and some from Project Gutenberg, etc.  I have school books, commentaries, reference books, and lots of childrens books (I homeschool).  Needless to say, I have already downloaded them onto ADE several times and they still disappear, but who wants to do that !? 

ADE's response is to disable ADE and reinstall it.  They didn't give any reasons for the missing books or for why ADE will no longer allow books to go into my Nook.  Now my Nook is saying that I don't have permission to open many books.   I wonder how much time these people would spend to fool around knowing that it probably won't work.

MY  QUESTION  NOW  IS:  Do I really have to put each one (other than B&N) back into ADE, and then again, individually, into my Nook?   I simply can't imagine doing that.  This was supposed to make my life easier.  I think I could have built bookshelves in the same amount of time.

I don't blame ADE for all the problems.  Barnes and Noble is poor in their instructions and left out much needed information, for the NOOK.   Christianbook.com had to show me how to download their books.  I never left click on "download", but right click instead, then click on "save link as".  A box pops up allowing me to write in the name (rather than a number) and where I want it to go (desktop).  I click on "save".

For "ascm" files, I just right click on "open" (from the desktop) and it automatically goes into ADE.  They are stored on the computer just as "epub" files are.  The ascm file icon must be deleted each time, or you can click on "replace" when the box pops up.  For "epub" files, I go into ADE and click on the little arrow by Library, and click on "Add item".  My computer opens a file with my "epubs" listed on the desktop.  I just click on whatever I want, whether one book, or many, and click "add". 

I have a Mac with Firefox, and everything is up to date.  When I want to select more than one book or file, I click on the first book, then go down to the last one, press "shift" and click the last book.   Unfortunately, we can't do that with the Nook.   ADE is so small on my screen that it is hard to read, and my mouse wiggles around quite a bit.  So, to put books back on my Nook, it will be a pain.

I did figure out, tho', to put books into one ereader and not mess with another, make sure the Wi-fi is off on the others.  I bought a Nook for my mom and daughter, but as they read different stuff, I learned the hard way, that I needed to load or archive books on each one separately.  Now they must keep their Wi-fi off unless they have a major change, which I will help them do.  (Neither one needs all the school books or children's books . . . Except for Jack and Jill, which every parent should read.)

I am still not sure how to fix my problems, but rest assured, I WILL !    I'm all for simplifying.  It makes it more confusing that Macs and PCs have different ways to do all this.   I'm glad I have a Mac.

I will let you know when I figure the rest out.

Wanda